Copolymers of ethyl-3-chloro-2-hydroxy-3-butenoate



COPOLYMIERS F ETHYL-3-CHLORO-2- HYDROXY-3 -B UTENOATE Harry A. Stanshury, South Charleston, and Howard R. Guest, Charleston, W. Va., assignors to Union Carbide Corporation, a corporation of New York No Drawing. Original application Nov. 12, 1954, Ser- No. 468,578. Divided and this application Dec. 2, 1957, Ser. No. 703,724

3 Claims. (Cl. 260-783) This invention relates to certain novel derivatives of 2-chloro-acrolein and more particularly to copolymers of monomers such as acrylonitrile and styrene with certain esters of 3-chloro-2-hydroxy-3-butenoic acid. The present application is a division of our parent application Serial No. 468,578 filed November 12, 1954, now Patent No. 2,865,952. The parent case is concerned with esters of the substituted butenoic acid per se, and the present case is concerned with copolymers of such esters and acrylonitrile or styrene.

The butenoic acid esters used in preparing the copolyrners of the present invention are characterized by the fact that they are tetrafunctional, and thus are capable of undergoing many different types of reaction. For example it has been found, as pointed out in more detail hereafter, that ethyl 3-chloro-2-hydroxy-3-butenoate can be readily copolymerized with styrene or acrylonitrile to form polymers that may be considered chlorhydrins, since they have adjacent chlorine and hydroxy groups. Both of such groups are capable of reaction to form modified polymers. More generally, the tetrafunctionality of nitecl States Patent 0 can be effected by treating the nitrile with alcohoiic by drochloric acid according to the following equation:

CH==C-CHOH-QN+CgH OH+H;O+HCI ent invention the following specific examples are given of methods of making the nitrile and ethyl ester of 3-chloro-2- l hydroxy-3-butenoic acid, as well as methods of copoly--- merizing the ester with styrene and acrylonitrile.

Example I .-Preparation of Z-chloroacrolein cyanohydrin;

from refined 2-chlorodcrolein A mixture of 0.6 grams of potassium cyanide (.0li equivalents) and 54grams of hydrogen cyanide. (2 moles) was stirred at'-3 C. to 0 C. While 180 grams of pure; 2-chloroacrolein (2 moles) were fed over a period of 30 minutes. After the solution was stirred at 0" C. for: 10 minutes longer, it was acidified with 1 cc. of concen trated, 37 percent hydrochloric acid. The crude product: was distilledunder reduced pressure toobtain 2-chloroacrolein cyanohydrjn having the following ;properties:

the present monomers makes them useful as starting materials in variety of polymerization, condensation and other types of reactions.

The butenoate monomers of the present invention can be conveniently prepared from acrolein. The acrolein is treated with chlorine to form 2,3-chloropropionaldehyde according to the following equation:

The 2,3-dichloropropionaldehyde thus formed is then converted to Z-chloroacrolein. Dehydrochlorination of the dichloropropionaldehyde is readily effected in the presence of hot Water The resulting 2-chloroacrolein is treated with hydrogen cyanide to form Z-chloroacrolein cyanohydrin which can also be described as the nitrile of 3-chloro-2-hydroxy-3- butenoic acid.

period of an hour.

boiling point at 3 mm. absolute-86 (3.; refractive index n 30-1.4665; specific gravity 20 01.250. molecular weight of .the product as determined by the Menzies-Wright method; was 116 as compared with at theoretical value of 117.5. Analysis of the product showed 30.9% chlorine and 11.3% nitrogen as compared with theoretical values of 30.2%, chlorine andll.9% nitrogen. The yield and efliciency were 79 percent.

Example H.Reaclion 0f Hydrogen cyanide with crude I Z-choroacrolein A solution of 114 grams of 97 percent arcolein (2 moles) in 228 grams of benzene was chlorinated at 0 C. to 5 C. until 142 grams (2 moles) had been absorbed to form 2,3-dichloropropionaldehyde. water was refluxed at atmospheric pressure the crude 2,3- dichloropropionaldehyde solution was fed thereto over a The top layer (oil) of the distillate was continually removed while the lower layer was re turned as reflux. The distillation was continued for 15- minutes to remove all of the steam-distillable oil from the system. The oil layer of the distillate weighed 319 grams and by analysis with hydroxylamine was found to conchloroacrolein solution.

A mixture of 0.4 gram of potassium cyanide catalyst (.006 equivalents) and 37 grams of hydrogen cyanide (1.38 moles, 10% excess) was stirred at 15 C.18 C..

while the 319 grams of 35.7 percent 2-chloroacrolein solution were added over a period of 45 minutes. Since very little heat was evolved, 0.4 gram more of potassium cyanide; catalyst (.006 equivalents) were added all at once. An ex-- othermic reaction imediately began and the maximum; temperature was held at 35 C. by strong cooling. After" the mixture was stirred at 10 C. to 20 C. for 30 minutes,. it was acidified with 1 cc. of concentrated hydrochloricacid. The crude product was distilled under reduced pressure to obtain 2-chloroacrolein cyanohydrin with 78 per cent yield and efliciency based on the crude 2-chloro acrolein.

While 2 liters of Example [IL-Preparation of ethyl 3-chloro-2-hydroxy- S-butenoate A mixture of 708 grams of anhydrous ethanol (15.4 moles), and 28 cc. of water (1.54 moles) was stirred at 25 C. to 45 C. while 124 grams of dry hydrogen chloride (3.4 moles) were added. Then 181 grams of L chloroacrolein cyanohydrin (1.54 moles) were fed at 40 C. to 45 C. over a period of 10 minutes. After the mixture was stirred and refluxed at 79 C. for 1.3 hours, it was cooled to 25 C. and filtered to remove ammonium chloride.

The filtrate was fractionated to obtain ethyl 3-chloro- Z-hydroxy-butenoate having the following properties: boiling point 63 C./3 mm. refractive index m n-1.4530; specific gravity at 20 C./ 20 C.1.202; molecular weight observed by the Menzies-Wright method159.8 (theory 164.5). Analysis showed the product to contain 21.9% chlorine, 43.3% carbon and 5.7% hydrogen, as compared with theoretical values of 21.6% chlorine, 43.8% carbon and 5.5% hydrogen. The compound was further identified as ethyl 3-chloro-2-hydroxy-3-butenoate (rather than an isomer) by investigation of its infra-red and ultra-violet absorption characteristcis.

Example IV.Cp0lymerization of ethyl-3-chlor0-2-hydroxy-3-butenoate and acrylonitrile A Pyrex tube was charged with 3.0 grams of ethyl-3- chloro-Z-hydroxy-3-butenoate, 7.0 grams of acrylonitrile, 10.0 ml. of acetone, and .25 ml. of a 25% solution of diacetyl peroxide in dimethyl phthalate. The gas phase was flushed with nitrogen, and the tube was then chilled in solid carbon dioxide and sealed, after which it was placed in a water bath maintained atSO" C. and rocked gently for 21 hours. At the end of this period the tube was gain chilled and broken open. The polymer was recovered by precipitation in isopropanol, filtered, and dried overnight in an air oven at 550 C. to 60 C. The polymer yield was 2.5 grams (25 conversion). It had a reduced viscosity of 0.28 in dimethylformamide at 30 C. and analyzed 7 3 polyacrylonitrile.

The copolymer is soluble in solvents, such as dimethylformamide, from which strong and flexible fibers, films and coatings can be prepared. Such copolymers have improved flame-resistance, anti-static properties, and adhesive qualities, contributed in the first instance, by their chlorine content, and in the other two instances by their hydroxyl content.

As compared to the non-chlorine containing ester, ethyl 2-hydroxy-3-butenoate, the chloro ester of this invention copolymerizes with acrylonitrile at a rate which is about twice as fast, and the resulting copolymers have a higher molecular weight. The following table presents data on comparative polymerizations, carried out under the same conditions given above:

ACRYLONIIRILE OOPOLYMERIZATIONS Percent Percent Relative 1 Reduced Acryloni- Acryloni- Rate of Viscosity Co-Monomer trile in trtle in Gopolyin Di- Mono- Copolymerizamethylmers mer tion forma- Oharged mide Ethyl 3-Chloro-2-hydroxy-3- 70.0 73.1 1.2 0. 28 30.0 51.8 2.5 bu noate 70.0 85.3 2. 5 0 30. 0 65. 8 4. 5 0.09

1 Acrylonitrile is the component having the faster rate of polymerization. Example V.Copolymerization 0f ethyl-3-chloro-2-hydr0xy-3-buten0ate and styrene 1 Using the procedure of Example IV a tube was charged with 3.0 grams of ethyl-3-chloro-2-hydroxy-3-butenoate, 7.0 grams of styrene, 10.0 ml. of benzene, and .25 ml. of a 25% solution of diacetyl peroxide. After 28.5 hours at C. the polymer yield was 1.3 grams (13% conversion). The polymer had a reduced viscosity of 0.13 in benzene at 30 C. and analyzed 5.6% of the butenoate, by chlorine analysis.

The copolymer is useful in forming film from benzene solutions which have improved anti-static properties.

What is claimed is:

1. As a new composition of matter, a copolymer of acrylonitrile and ethyl 3-chloro-2-hydroxy-3-butenoate.

2. As a new composition of matter, a copolymer of styrene and ethyl 3-chloro-2-hydroxy-3-butenoate.

3. As a new composition of matter a copolymer of ethyl 3-chloro-2-hydroxy-3-butenoate and a monomer selected from the group consisting of acrylonitrile and I styrene.

No references cited. 

3. AS A NEW COMPOSITION OF MATTER COPOLYMER OF ETHYL-3-CHLORO-2-HYDROXY-3-BUTENOATE AND A MONOMER SELECTED FROM THE GROUP CONSISTING OF ACRYLONITRILE AND STYRENE. 